Evaluation of high-resolution regional climate model performance over Surabaya metropolitan area using RegCM5 MOLOCH core

As climate change continue to impact weather patterns globally, understanding regional effects has become more important. Traditional global climate model lacks the resolution to capture the dynamics of regional climate, leading to uncertainties in predicting local climate. There has been some research about high-resolution regional climate model, but not specific to Indonesia especially Surabaya. This paper aim is to evaluate the new MOLOCH non-hydrodynamical core of RegCM5 in producing high-resolution regional climate model. This study covers Surabaya Metropolitan Area, with a period of December 2017 to November 2019. Three different scheme combinations were compared, two of which were based on previous research, and one is a new combination. ERA5 0.25° 6-hour surface and sea surface temperature datasets were utilized as the global climate model. It can be observed that the model had a cold bias for the maximum temperature and warm bias for the minimum temperature. As for precipitation and surface upwelling longwave radiation the model performed well, and it had a similar pattern with a small bias. Overall, the MOLOCH core performed well, but the model produced limited temperature variability as opposed to the observed data. The findings might shed light on the future of regional climate modelling.